Long-term Outcomes of Lupus Nephritis in Comparison to Other CKD Etiologies

Introduction: Little is known regarding the comparison of cardiovascular and kidney outcomes between lupus nephritis (LN) and other etiologies of chronic kidney disease (CKD).

Methods: Using data from the Swedish Renal Registry (2006-2021), we compared long-term outcomes between patients with LN-CKD and patients with CKD due to primary glomerular diseases (PGD) and other CKD causes (Other-CKD, mainly diabetes and nephroangiosclerosis). Adjusted hazard ratios (HRs) of mortality, major adverse cardiovascular events (MACE) and kidney replacement therapy (KRT) were estimated using Cox proportional hazard models.

Results: At baseline, LN (n = 317, 61 years, 76% women) and PGD (n = 2296, 57 years, 30% women) had better kidney function and lower prevalence of cardiovascular disease than the Other-CKD (n = 34,778, 75 years, 36% women). The median follow-up was 6.2 (3.3-9.8) years. The absolute risks of death and MACE in LN-CKD were intermediate between those of Other-CKD and PGD. The 5-year absolute KRT risk of LN-CKD was similar to Other-CKD's risk (22%) and lower than in PGD (37%). In multivariable analysis, as compared to PGD, the rates of death and MACE in LN-CKD were higher (HR: 1.63 [95% confidence interval: 1.32-2.02] and 1.65 [1.31-2.08]), whereas the rate of KRT tended to be lower (0.81 [0.64-1.02]). In contrast, the rate of adverse events was not different between LN-CKD and Other-CKD.

Conclusion: Although patients with LN-CKD had a lower risk of KRT than PGD-CKD, they exhibited higher risk of death and MACE, reaching the risk magnitude of patients with high cardiovascular burden (Other-CKD). Our findings may inform decisions about prevention of cardiovascular events in patients with moderate and advanced LN-CKD.